ORIGINAL RESEARCH article
Front. Immunol.
Sec. Cancer Immunity and Immunotherapy
Volume 16 - 2025 | doi: 10.3389/fimmu.2025.1672790
This article is part of the Research TopicAdvancements and Challenges in Veterinary Oncology - Volume IIView all articles
Phase 2 Trial (NCI-COTC030) of adjuvant inhaled recombinant human IL-15 combined with amputation and adjuvant chemotherapy in dogs with appendicular osteosarcoma
Provisionally accepted- 1University of California Davis Department of Surgical and Radiological Sciences, Davis, United States
- 2Division of Surgical Oncology, Department of Surgery, University of California, Davis, Sacramento, United States
- 3Comparative Oncology Program, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, United States
- 4Artificial Intelligence Resource, Molecular Imaging Branch, National Cancer Institute, NIH, Bethesda, United States
- 5Departments of Medicine (Hematology and Oncology) and Microbiology & Immunology, Medical College of Wisconsin, Milwaukee, United States
- 6University of Wisconsin-Madison School of Veterinary Medicine, Madison, United States
- 7University of Wisconsin-Madison Carbone Cancer Center, Madison, United States
- 8Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, United States
- 9Department of Clinical Sciences, Colorado State University College of Veterinary Medicine, Fort Collins, United States
- 10Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, United States
- 11University of California Davis Department of Public Health Sciences, Davis, United States
- 12Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, United States
- 13Veterinary Center for Clinical Trials, Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California, Davis, Davis, United States
- 14Division of Cancer Treatment and Diagnosis, National Cancer Institute, National Institutes of Health, Rockville, United States
- 15Department of Dermatology, University of California, Davis, Davis, United States
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
Background: We have previously shown inhaled IL-15 is associated with anti-tumor responses in dogs with metastatic osteosarcoma (OSA) and melanoma. We evaluated inhaled IL-15 combined with amputation and chemotherapy for localized canine OSA eligible for treatment with curative intent. Methods: In a multicenter COTC phase-II-trial for dogs with limb OSA, we hypothesized 2 weeks of inhaled rhIL-15 after amputation and prior to chemotherapy would reduce the risk of metastatic failure at the completion of chemotherapy from a historical rate of 40% to 20%. Using a 2-sided alpha of 0.05, we planned an accrual of 40 dogs to test this hypothesis with 80% power. We performed immune correlative assays and sequencing of peripheral blood mononuclear cells (PBMCs) and primary amputation specimens. Results: Unexpectedly, disease-free survival and overall survival were statistically inferior for dogs in the intent-to-treat population compared to a well-validated historical control cohort, so the trial was halted for futility. Cytotoxicity assays of PBMCs showed significant decreases after both surgery and chemotherapy with an overall decrease from the start to end of therapy (-18.2±16.1%, P<0.001). Some dogs demonstrated positive fold change in PBMC cytotoxicity, which correlated significantly with improved dog survival (P=0.004, r=0.62). Although plasma concentrations of key cytokines varied markedly with no significant differences between disease-free and metastatic-failure patients, inflammatory cytokines such as IL-6 showed absolute increases post-amputation and post-chemotherapy, correlating with decreases in cytotoxicity. Tumor sequencing data reproduced immune signatures as observed in both human and canine cohorts, and PBMC single cell sequencing data showed that gene expression profiles of NK and T cells were significantly different between short and long disease-free interval subjects. Conclusions: Inhaled rhIL-15 combined with amputation and chemotherapy is associated with worse outcomes in dogs with OSA. Correlative assays suggest significant immunological effects of amputation and chemotherapy on immune responses. These data have important implications on novel immunotherapy strategies involving multimodality approaches including surgery and chemotherapy.
Keywords: Osteosarcoma, Immunotherapy, Interleukin-15, Canine oncology, adjuvant
Received: 24 Jul 2025; Accepted: 09 Oct 2025.
Copyright: © 2025 Rebhun, Cruz, York, Mazcko, Razmara, Patkar, Judge, Sholevar, Shah, Zamora, Al-Nadaf, Vail, Fan, Burton, Luker, Skorupski, Lejeune, Woolard, Stewart, Sparger, Young, Cohen-Davidyan, Huang, Beck, Murphy, Kent, Culp, LeBlanc and Canter. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence:
Robert B Rebhun, rbrebhun@ucdavis.edu
Robert J Canter, rjcanter@health.ucdavis.edu
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.